RAM, that means Random Access Memory, is a computer storage media which can be accessed much more quickly than a disk drive, as the data can be read randomly, skipping the bytes before the needed data is reached. On a web server, the RAM is used to load scripts and web apps once they are executed, so the more RAM you can use, the more apps you'll be able to run all at once and the more people will be able to explore your websites without any effect on the site’s/server’s general performance. In contrast to a disk drive, however, the RAM is used for momentary storage purposes, due to the fact that the info is lost when the power is shut off. When you use a shared web hosting account, the physical memory that your scripts may use may be limited and might change based upon what the some other clients on the same hosting server use. Using a virtual or a dedicated server, on the other hand, you shall have a guaranteed amount of RAM that won't be used by anyone else even if you do not use it at a particular time.